#include <iostream>
using namespace std;
int stack[100], n=100, top=-1;
void push(int val)
{
   if(top>=n-1)
   cout<<"Stack Overflow"<<endl;
   else
   {
      top++;
      stack[top]=val;
   }
}
void pop()
{
   if(top<=-1)
   cout<<"Stack Underflow"<<endl;
   else
   {
      cout<<"The popped element is "<< stack[top] <<endl;
      top--;
   }
}
void display()
{
   if(top>=0) 
   {
      cout<<"Stack elements are:";
      for(int i=top; i>=0; i--)
      cout<<stack[i]<<" ";
      cout<<endl;
   }
   else
   cout<<"Stack is empty";
}
int main() 
{
   int ch, val;
   cout<<"1) Push in stack"<<endl;
   cout<<"2) Pop from stack"<<endl;
   cout<<"3) Display stack"<<endl;
   cout<<"4) Exit"<<endl;
   do
   {
      cout<<"Enter choice: "<<endl;
      cin>>ch;
      switch(ch)
      {
         case 1:
         {
            cout<<"Enter value to be pushed:"<<endl;
            cin>>val;
            push(val);
            break;
         }
         case 2:
         {
            pop();
            break;
         }
         case 3: 
         {
            display();
            break;
         }
         case 4:
         {
            cout<<"Exit"<<endl;
            break;
         }
         default: 
         {
            cout<<"Invalid Choice"<<endl;
         }
      }
   }
   while(ch!=4);
   return 0;
}
